The assembly of the carbohydrate units of both soluble and membrane glycoproteins is being investigated with the use of (14C)-labeled precursors in cell-free, slice and in vivo systems from renal cortex, thyroid and adipose tissue. The enzymes and intermediates involved in this process are being characterized and information about control mechanisms is being sought. BIBLIOGRAPHIC REFERENCES: Spiro. R. G., Search for a biochemical basis of diabetic microangiopathy. Diabetologia 12,1-14(1976). Spiro, M. J., Spiro, R. G., and Bhoyroo, V. D., Lipid intermediates in glycoprotein biosynthesis: Formation by thyroid of an oligosaccharide-lipid containing glucose. Fed. Proc. 35, 1375(1976).